SR20 Bore 86.5 or 87mm - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

bowflex · 02-02-2009, 01:25 PM

does anyone know the hp gain difference between 86.5 to 87mm? I have 86mm bore currently but have to bore to at least 86.5 and am trying to decide whether or not to go up another .5 mm. I don't want to shorten the life of my engine, but since I have to increase the bore anyway I want to know if I should go a little more.

n240sxfnatic · 02-02-2009, 02:33 PM

People dont do it for a hp gain, which I doubt there is on .5mm. They do it when rebuilding because it is recommended.

EDacIouSX · 02-02-2009, 02:46 PM

do the least amount of bore you have to do. 86.5 is good, that way next time you rebuild you can do 87. i think the max bore is 87.5?? 88? then i THINK? you have to sleeve it or something. i am not familiar with sleeving....

http://www.tomei-p.co.jp/_2003web-ca...20_piston.html

looks like 87.5 is biggest.

*fliprayzin240sx* · 02-02-2009, 05:25 PM

A good rule of thumb has been anything more than 87mm, have fun sleeving the block.

Jodan · 02-03-2009, 12:48 PM

90mm ya pansy!

jk. go with the least amount you can get away with.

EmmanuelTucay · 02-03-2009, 01:03 PM

Stroke it!

02-02-2009, 01:25 PM	#1
bowflex Join Date: Oct 2007 Location: Colorado Springs Age: 33 Posts: 38 Trader Rating: (0) Feedback Score: 0 reviews	SR20 Bore 86.5 or 87mm does anyone know the hp gain difference between 86.5 to 87mm? I have 86mm bore currently but have to bore to at least 86.5 and am trying to decide whether or not to go up another .5 mm. I don't want to shorten the life of my engine, but since I have to increase the bore anyway I want to know if I should go a little more.

02-02-2009, 05:25 PM	#4
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	A good rule of thumb has been anything more than 87mm, have fun sleeving the block. __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

02-03-2009, 12:48 PM	#5
Jodan Zilvia Member Join Date: Jan 2008 Location: Eastern west side Posts: 161 Trader Rating: (0) Feedback Score: 0 reviews	90mm ya pansy! jk. go with the least amount you can get away with. __________________

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02-02-2009, 02:33 PM	#2
n240sxfnatic Zilvia Junkie Join Date: Apr 2007 Location: West Des Moines, Ia Age: 33 Posts: 493 Trader Rating: (6) Feedback Score: 6 reviews	People dont do it for a hp gain, which I doubt there is on .5mm. They do it when rebuilding because it is recommended.

02-02-2009, 02:46 PM	#3
EDacIouSX Post Whore! Join Date: Nov 2004 Location: Los Angeles Age: 35 Posts: 4,527 Trader Rating: (53) Rides Gallery: EDacIouSX Feedback Score: 53 reviews	do the least amount of bore you have to do. 86.5 is good, that way next time you rebuild you can do 87. i think the max bore is 87.5?? 88? then i THINK? you have to sleeve it or something. i am not familiar with sleeving.... http://www.tomei-p.co.jp/_2003web-ca...20_piston.html looks like 87.5 is biggest.

02-03-2009, 01:03 PM	#6
EmmanuelTucay BANNED Join Date: Dec 2008 Location: Cerritos Age: 36 Posts: 54 Trader Rating: (0) Feedback Score: 0 reviews	Stroke it!